1. Field of the Invention
The present invention relates to mixtures of reactive dyes, which are particularly suitable for dyeing fabric materials. They display good build-up, wash fastness, and levelness; especially low nylon cross-staining in blended and interwoven fabrics.
2. Description of the Related Art
To date it has been difficult to find a single reactive dye which displays good build-up to heavy black shades. In order to gain good build-up in black shades, a reactive dye composition, which contains a number of reactive dye components, has been used.
One black reactive dye (for example, the following formula (I) black reactive dye) as the major component is usually mixed 
with red, orange, yellow or other shade reactive dyes to yield black reactive dye compositions.
Black reactive dye compositions are already known from Japanese Patent Laid-open No. 58-160362, 63-178170, 1-315469, 2-73870, 2-202956, 8-104822, and 8-253697, and U.S. Pat. Nos. 5,445,654, 5,611,821, 5,780,602, 5,849,887, 5,931,974 and 6,127,700.
In order to achieve high quality fabric, a blended or interweave fabric, which contains two different fibers, has been produced and sold in the market.
When dyeing the blended fabrics, problems can be encountered in off-tone dyeing because different fibres have different affinities for the dyestuffs. Especially when dyeing nylon/cellulose blended fabrics, it is difficult to get a low nylon cross-staining product. Therefore it is necessary to select appropriate dyestuffs when dyeing blended or interwoven fabrics.
There are many black reactive dye compositions which can be chosen in the market. However the black dye compositions with little nylon cross-staining always show poor properties in levelness and build-up. Conversely, black dye compositions with good properties in levelness and build up always stain nylon badly.
Therefore, there is a strong demand for a reactive black dye composition having good dyeing properties and low nylon cross-staining.
It is one object of the present invention to provide a reactive black dye composition that is suitable for use in exhaustion, printing, continuous dyeing or discharge printing of fibers to provide good dyeing properties.
Other objects of the present invention are to provide a reactive dye composition, which has good build-up properties, wash fastness, wash-off, levelness and low nylon cross-staining of blended or interwoven fabrics.
The reactive dye composition of present invention comprises: one or more, such as one, two or three, disazo dyes conforming to component (A), one or more, such as one, two or three, disazo dyes conforming to component (B) and optionally one or two monoazo dyes conforming to component (C).
Component (A) is selected from disazo dyes which may be represented by formula (I) to formula (III), 
wherein Y is xe2x80x94CHxe2x95x90CH2 or xe2x80x94C2H4W, W is a leaving group which can be eliminated by a base; R1 and R2 are each independently hydrogen, methyl, ethyl, methoxy, ethoxy or sulfonic acid, preferably hydrogen or methoxy, and most preferably hydrogen. The leaving group W is for example, xe2x80x94Cl, xe2x80x94Br, xe2x80x94F, xe2x80x94OSO3H, xe2x80x94SSO3H, xe2x80x94OCOxe2x80x94OCH3, xe2x80x94OPO3H2, xe2x80x94OCOxe2x80x94C6H5, xe2x80x94OSO2xe2x80x94(C1-C4-alkyl) or xe2x80x94OSO2xe2x80x94N(C1-C4-alkyl)2. W is preferably xe2x80x94Cl, xe2x80x94OSO3H, xe2x80x94SSO3H, xe2x80x94OCOxe2x80x94CH3, xe2x80x94OCOxe2x80x94C6H5 or xe2x80x94OPO3H2, more preferably xe2x80x94Cl or xe2x80x94OSO3H and, particularly preferably, xe2x80x94OSO3H.
Component (B) is selected from the reactive disazo dye which may be represented by formula (IV) to formula (XI), 
wherein Y, R1 and R2 are defined as the above; R3 and R4 are each independently hydrogen, methyl, ethyl, methoxy, ethoxy or sulfonic acid, preferably hydrogen or methoxy, particularly preferably hydrogen; R5 is amino, xe2x80x94NHC2H4COOH or xe2x80x94NHCOCH3; R6 is methyl, ethyl, propyl or carboxylic acid; R7 is amino, xe2x80x94NHC2H4COOH, xe2x80x94NHCONH2 or xe2x80x94NHCOCH3; R8 and R9 are each independently hydrogen, amino or sulfonic acid; and R10 is xe2x80x94CH2SO3H or xe2x80x94CONH2.
Furthermore, the reactive black dye composition of the present invention can contain component (C) with at least a reactive monoazo dye of formula (15), (16) or (17). 
The dyestuffs of the present invention all contain anionic groups, such as a sulfonic acid groups: for convenience they are depicted as free acid in the specification. When the dyestuffs of the present invention are manufactured, purified or used, they exist in the form of water soluble salts, especially alkaline metallic salts, such as sodium salts, potassium salts or ammonium salts.
The ratio of each dye component can be changed over a wide range. In general, the minimum relative weight percentage for each dye component is 3%, and the maximum relative weight percentage is 90%. The dye composition of the present invention preferably contains component (A) 30xcx9c80% by weight, component (B) 25xcx9c75% by weight, and optionally component (C) 0xcx9c45% by weight.
The compounds represented by formula (I) of the present invention can be synthesized by the following method.
First, the diazonium salt derived from the amine of the formula (a) 
wherein Y, which is defined as the above, is coupled with compound (b) 
under acidic conditions. The monoazo compound thus obtained is then reacted with a diazonium salt, derived from an aromatic amine (c), 
wherein Y, R1, and R2 are defined as above under a basic conditions to yield a compound of formula (I).
Examples of formula (I) are formula (1), formula (2) or formula (3). 
The compound of formula (II) can be synthesized by the following method.
First the tetrazonium salt derived from the aromatic diamine (d) 
is coupled with a compound of formula (b) under acidic conditions. The compound thus obtained is then reacted with the diazonium salt derived from the amine (c) under basic conditions, to yield a compound of formula (II).
An example of formula (II) is formula (4). 
Compounds of formula (III) of the present invention can be synthesized by the following method.
First, the compound of formula (e) is condensed with compound of formula (f). 
The resulting product is diazotised and the diazonium salt thus obtained is coupled with a compound of formula (b), under acidic conditions, then coupled with the diazonium salt derived from amine (g), under basic conditions. Finally it is condensed with a compound of formula (h) to yield a compound of formula (III), wherein Y is defined as above. 
An example of a compound of formula (III) is a compound of formula (5). 
Compounds of formula (IV) and formula (V) of the present invention, can be synthesized by the following method. The diazonium salt derived from an amine (c) is coupled with a compound of formula (i), 
the resulting monoazo derivative is then diazotised and coupled with a compound of formula (j) or a compound of formula (k), 
wherein R6 is defined as the above.
Examples of compound of formula (IV) and (V) are formula (6) and (7). 
Compounds of formula (VI) and (VIII) can be synthesized by the following method.
The diazonium salt derived from amine (c) is coupled with a compound of formula (m), and the resulting monoazo derivative is 
then diazotised. The diazonium salt thus obtained is coupled with a compound of formula (k) or (j).
Examples of formula (VI) are formula (8), (9) and an example of formula (VIII) is formula (10). 
Formula (VII), (IX) and (XI) of the present invention can be synthesized by the following method.
The diazonium salt derived from amine (c) is coupled with a compound of formula (n) 
wherein R5 is defined as above, and the resulting monoazo derivative is diazotised. The diazonium salt thus obtained is coupled with a compounds of formula (o), (p) or (q). 
wherein R3, R4, R6, R7, R8, R9 and R10 are defined as the above.
Examples of formula (VII), (IX) and (XI) are formulae (11), (12) and (13) respectively. 
Compounds of formula (X) can be synthesized by the following method.
The diazonium salt derived from amine (s) is coupled with a compound of formula (o), then hydrolyzed in aqueous alkali at refluxing, to yield a compound of formula (t), 
wherein R5, R7, R8 and R9 are defined as above. Finally, the compound of formula (t) is coupled with a diazonium salt derived from an amine (c).
An example of formula (X) is formula (14). 
The compositions of the present invention can be prepared in many ways. For example, by using separately prepared dye components and mixing together to make powder, granular or liquid form, or by mixing a number of individual dyes as a dyeing recipe in a dye house. The dye mixtures of this invention can be prepared, for example, by mixing the individuals dyes. The mixing process is carried out, for example, in a suitable mill, e.g. in a ball mill, pin mill, or in kneaders or mixers. If the dyestuff mixtures of the invention are prepared by mechanical mixing of the individual dyestuffs, any necessary standardizing agents, dust removal agents or further auxiliaries, which are customary in dyeing, and are customary in dyestuff preparations, used in this context are added during mixing.
The dyestuffs of present invention can be in the form of powders, granules or liquids; and an auxiliary agent, for example, a retarding agent, leveling agent, assistant agent, surfactant, or dispersing agent may be added.
The dye compositions of the present invention can be in solid or in liquid form. In the solid form, they may generally contain electrolyte salts customary for water-soluble and in particular fiber-reactive dyestuffs, such as sodium chloride, potassium chloride and sodium sulfate. Furthermore they can contain auxiliaries customary in commercial dyestuffs, such as buffer substances, which are capable of establishing a pH in aqueous solution of between 3 and 7, such as sodium acetate, sodium borate, sodium bicarbonate, sodium dihydrogen phosphate, and disodium hydrogen phosphate or agents which improve the solubility, such as known naphthalenesulfonic acid-formaldehyde condensation products, methylnaphthalenesulfonic acid-formaldehyde condensation products, acetylaminonaphthol based compounds, etc. If they are liquid, aqueous solution (including the content of thickeners, such as are customary in printing pastes), they may contain dissolved the above-mentioned substances and may contain substances which ensure the storage stability of these preparations, such as mould-preventing agents.
The ratio of each dye component can be changed over a wide range. In general, the minimum relative weight percentage for each dye component is 3%, and the maximum relative weight percentage is 90%. The dye composition of the present invention preferably contains component (A) 30xcx9c80% by weight, component (B) 25xcx9c75% by weight, and optionally component (C) 0xcx9c45% by weight.
The black dye compositions of the present invention can be used to dye a wide range of natural and synthetic fibres which contain either amino or hydroxyl groups, such as wool, silk and synthetic polyamides. These dye compositions can also be used to dye natural cellulosic fibres such as cotton, linen, ramie, jute as well as regenerated cellulosic fibres. The dyeing method used is the one generally used when a reactive dyestuff is applied to the appropriate substrate. In the case of dyeing cellulose, the substrate is added to an aqueous bath containing the required amount of inorganic electrolyte (common salt or sodium sulfate) to achieve a high level of exhaustion. The covalent bond, connecting the dye to the cellulosic fibre, is formed on the addition of alkali (soda ash, sodium bicarbonate or caustic soda).
The black dye composition of the present invention is of high industrial importance. It allows level, heavy (deep black) shades to be obtained with minimal amounts of cross staining of polyamide when dyeing a cotton/nylon blend.
Many examples have been used to illustrate the present invention. The examples sited below should not be taken as a limit to the scope of the current invention. In these examples, the compound is represented by the free acid. However, in practice, it will exist as a (metal) salt, for example as the sodium, lithium, potassium or ammonium salt, particularly the sodium salt. In the following examples, quantities are given as parts by weight (%) and temperature are given in degree Celsius.